>>10778
Probably tricyclic antidepressants.
Not commonly prescribed these days precisely due to the fact that they can kill you so easily if you OD, and suicidal tendencies/ideation are a well known common side-effect of antidepressant usage. They're only considered useful in forms of depression which have been resistant to conventional SSRI/SNRI treatment.
I had a journal reference somewhere that I can't find now which mentioned that at one point in time something like 25% of OD suicides in the United Kingdom were done with tricyclics.